>Concerning the material used for inner rim laminations, I wonder how >critical it really is tonally. The inner rim, of course, has several >functions -- 1) to provide an immovable surround the for the framing (back >or Rast) into which the braces can be securely dovetailed, 2) to provide a >solid medium into which the string-plate bolts can be screwed, 3) to add >rigidity to the outer rim when this is glued on and 4) to provide, at its >outer edges only, and in combination with the outer rim, a massive and >solid frame for the soundboard. Hi John, Something between the string and the ear has to be stiff or the piano will dump all it's string energy at once and sound like a banjo. A thicker and stiffer soundboard will somewhat compensate for lack of stiffness in the rim, as will a stiffer bridge. The tradeoff for the increased sustain achieved is a loss of volume, so you go to a heavier and harder hammer to jack it up. That effectively eliminates the low end of the dynamic range and sells a lot of ear plugs to tuners, but you now have volume and sustain - if not musicality. You also get pianos that are very dependably uniform from instrument to instrument since the subtleties of the material properties are overpowered in the brute force approach. A stiff and massive rim, on the other hand, doesn't absorb and damp the soundboard's energy as rapidly as a less stiff and massive rim (though it obviously will to some degree no matter how stiff and massive it is), and lets you use a lighter and more responsive soundboard assembly, which lets you use a softer, more resilient hammer and get a broader dynamic range while still having good volume and sustain. There are probably a near infinite combination of stiffness/mass combinations in various component parts of the system that would produce a sound someone would buy. My assumption with that Yamaha rim I mentioned was that it was intended to stiffen the rim assembly somewhat and still be easier to bend and possible to produce in a short cycle production process than an all maple rim. That's why I asked, to see if anyone could verify or correct my assumption. Ron N
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